▀▄ eas | Bang for the Buck Mods: Macht Schnell UDPs & Dyno Findings

[tom @ eas]

Often the question is asked: What is the biggest bang for the buck mod in terms of hp gains? The most common answers given are the following:

Intake
Macht Schnell Performance Filter: 5-6hp @ $99 = $16/hp
Macht Schnell S2 Intake Kit: 10-12hp @ $499 = $41/hp

Exhaust
Challenge Stainless Steel RACE X-Pipe Race: ~20hp @ $1695 = $85/hp
Akrapovic Evolution Titanium Exhaust System: ~25hp @ $5990 = $236/hp

On the extreme side (as well as budget) and the ultimate fix, we can look into supercharging:

VF620 Supercharger: ~170hp @ $13,900 = $82/hp



Right in the middle, we have the unsung hero. UnderDrive pulleys.

Macht Schnell UnderDrive Pulleys: ~10hp @ $395 = $39.5/hp

The concept is simple: limit parasitic drag from the accessories within a safe & moderate level for maximum performance. Due to the reduction in power required to turn accessories; an increase in rotating assembly lifespan is (due to lower speed) will also result. Gains are due to a reduction in power required to turn accessories.

The DualDrive design of the Macht Schnell pulleys replaces the Crank Accessory & Power Steering Pulleys, resulting in a 9-14 HP and 7-9ft. lbs TQ gain for the M3.

Machined from 6061-T6 aerospace aluminum, Macht Schnell Performance Underdrive Pulley sets are strong as well as lightweight. After machining and engraving, pulleys are then T3 hard anodized for additional strength, anti-corrosion & wear resistance. All factory harmonics/balancing are undisturbed.

Using a simple acceleration test, we can see the gains in 1st-4th Gear on the dyno:

Acceleration Test: Standard Correction


Acceleration Test: SAE Correction


Vehicle Info
Vehicle: 2011 BMW M3
Transmission: DCT
Modifications: Macht Schnell UDPs
Software: Stock
Fuel: 91 Octane

Ignoring the TQ spikes, we can see gains are present throughout the powerband, while maintaining safe levels on vitals. Our testing shows consistent to posted claims.

Using 2 pulleys instead of the standard singe Underdrive set allows for multiple features:

- Ability to use readily available accessory belts found at any auto part supply house
- A/C compressor is not underdriven, since clutch is already designed to be disengaged at WOT, allowing driver to retain comfort levels in hotter climates
- DualDrive Pulley design replaces the proprietary dual-ribbed belts, eliminating the need for custom belts to be made and allowing off-the-shelf belts to be used during maintenance. Replacement belts are available at any local parts supply warehouse.

Macht Schnell Performance Underdrive Pulleys Features
- DualDrive design allows maximum performance, with minor affect on accessory speed
- DualDrive design eliminates proprietary dual-ribbed belt design. Replacement belts can be found at any local parts warehouse
- Proper cooling temperatures are retained at proper levels on or off the track
- Maintains proper alternator speed, allowing sustained levels to sensitive control modules
- Machined from 6061-T6 aerospace aluminum
- T3 Hard-Anodized for maximum strength and corrosion/wear resistance
- No affects to crankshaft dampening or harmonics

Macht Schnell Performance Underdrive Pulleys have no negative effect on accessory operation and come fully equipped with new belts. Installation is only about 60-90 minutes and can be performed by your local installer or by those with DIY type skills.

Choosing the correct mods to work together as a system will give you the best overall driving experience.

Enjoy!

[PAKMAN]

niceee thanks for the info Tom!

[tha_good_life]

thanks!

[THE TECH]

I like mine! Prob need to dyno at some point though.

[Orange fever]

so much win here

[TMR]

Damn, i wish i could get these right now! Gains look good.

[Robmaster]

no cooling issue??

[M3_WC]

Akrapovic is amazing. But never heard any say "Akrapovic" and "bang for your buck" in the same sentence.

[saeedg48]

tom - awesome thread! thanks

[crabman]

The filter runs fall into noise, an underdrive pulley works but if there was more to be had without any downside the OEM manufacturer would have already taken every spec of it because efficiency mods of that type are free from their standpoint. Other than that as usual with almost any car FI comes out to the cheapest per dollar hp. Am I missing something?

[tom @ eas]

Originally Posted by Robmaster

no cooling issue??

Reduction is kept within safe limits. No cooling issues on either the street or even extended sessions on the track with UDPs.